S3255 Frequency of Cirrhosis Diagnostic Disagreement Between Liver Ultrasound and Elastography

Abstract

INTRODUCTION: Ultrasound (US) and shear wave elastography (SWE) are currently used for evaluation of patients with various etiologies of chronic liver diseases, especially hepatitis C. However, frequently, anecdotally we have noted occasional disagreement between the results of US and SWE. The objectives of this study were to assess the frequency of diagnostic disagreement between liver US and SWE, and to determine each method’s frequency of a correct diagnosis during diagnostic disagreement. METHODS: Both US and SWE were prospectively performed on patients referred for evaluation for liver diseases (n = 1,206). US diagnosis of cirrhosis was based on the presence of enlarged left lobe, increased caudate to right lobe ratio and/or surface nodularity. SWE diagnosis of cirrhosis was based on the presence of liver stiffness more than 12 kPa. When there was disagreement between US and SWE, clinical evaluations (ascites, hepatic encephalopathy or variceal bleeding), other imaging (CT or MRI), laboratory findings (albumin <3.2, platelets <125 or INR >1.2), and/or liver biopsies were used to confirm the correct diagnosis. Measures of central tendency and frequency distributions were used to characterize 1) the sample, 2) the frequency of diagnostic agreement and disagreement, 3) and the frequency of a correct diagnosis. RESULTS: The age, sex, race and etiology of liver disease are shown in Table 1. The most frequent etiology was HCV, 770 patients (73%) followed by NASH, 114 (10%). The frequency of diagnostic disagreement on cirrhosis between US and SWE was 13% (160/1,191). In cases of disagreement, another imaging modality (CT or MRI), labs, clinical judgment or liver biopsy (if available) were used to confirm the diagnosis. SWE was correct in 62% (98/158) and US was correct in 38% (60/158) of cases when there was diagnostic disagreement. CONCLUSION: Disagreement between US and SWE in the diagnosis of cirrhosis is relatively common. In cases of disagreement, findings from this relatively large prospective study suggest SWE is more likely to provide the correct diagnosis.Table 1.: Sample Characteristics and Frequency of Diagnostic Disagreement